1. Field
The inventive concept relates to a monitoring device applicable to a distributed antenna system (DAS).
2. Description of Related Art
Conventionally, there was used a method in which, when a service error occurred in a distributed antenna system (DAS) network, a manager directly checked whether a corresponding equipment was abnormal using a spectrum analyzer at a place where equipments constituting the DAS network were located.
However, the conventional method has the following problems when the manager monitors an error of the DAS network. For example, in the DAS network, a plurality of node units such as a head-end (HE) unit, a plurality of hub units, and a plurality of remote units are communicatively coupled to each other, and therefore, the manager has difficulty in detecting in which part a problem has occurred. Also, when the DAS network is applied to a subway, a relay tower, etc., a manager's access is limited, and therefore, the manager has difficulty in checking whether an error has occurred. Also, when a problem occurs in a service due to an error of a signal input from a base station, an abnormality of an optical fiber, a defect of a remote unit, etc., the manager has difficulty in detecting an accurate cause. Also, when a service signal is degraded due to a defect of a power amplification unit (PAU), the manager has difficulty in detecting an accurate cause. Also, when a problem occurs in a reverse service due to a defect of a specific remote node, the manager has difficulty in detecting an abnormally operating remote unit. Also, in the DAS network to which a direct digital interface (DDI) such as a common public radio interface/open base station architecture initiative is applied, the manager cannot analyze the occurrence cause, position, and the like of a failure by using the conventional method.